Friday, April 21, 2017

Q: How is the march integrating inclusion, diversity, equity, and access?

A: Inclusion, diversity, equity, and accessibility are integral to our mission and to our overall goals and principles. We cannot ignore issues of racism, sexism, homophobia, ableism, xenophobia, or any other form of discrimination in the discussion and implementation of science. Nor can we ignore the ways in which science has been misused to harm marginalized communities. The lack of inclusivity and diversity in STEM thwarts scientific advancements not only by limiting who conducts the research, but also by influencing what topics are studied, who participates in the research, and who will benefit from or be harmed by it. We are actively working with partner organizations and experts on these issues and march organizers come from and stand in solidarity with historically underrepresented scientists, science advocates, and communities impacted by attacks on science.

This is a leftist political action.

Some scientists have the attitude of just seeking truth, and leaving the social consequences to policymakers. Not these leftist organizers. Their idea of science is promoting what they see as the common good, and they have a leftist view of what that is.

Monday, April 17, 2017

If you ask Google to search for “no quantum world,” you will get nearly 300 hits. They all give the following quotation (or recognizable corruptions of it):

There is no quantum world. There is only an abstract quantum physical description. It is wrong to think that the task of physics is to find out how nature is. Physics concerns what we can say about nature.

Over 90% of them attribute the statement to Niels Bohr, with phrases like “Bohr’s dictum ...,” “Bohr insisted that ...,” “Bohr proclaimed ...,” “Niels Bohr said, in a frequently quoted passage ...,” “Niels Bohr wrote [my emphasis] ...,” and even “Explain and evaluate Bohr’s philosophy of quantum theory with reference to his assertion ... .”

Mermin is unable to confirm that Bohr said exactly those words, and gets conflicting opinions about whether it correctly reflects what Bohr did say.

Of course, for the post-1927 Einstein the wavefunction is, as we have seen, essentially a probability distribution over hidden ontic states; it is (at least) these ontic states that correspond to a "concept" that is "independent of experience", if we are "thinking physically". According to Einstein, orthodox quantum mechanics is incomplete precisely because it does not specify what such ontic states are. The idea that quantum physics can do without them altogether seems to me to be antithetical to Einstein’s program, metaphysically shy though it is.

Brown goes on to criticize those who claim to have some interpretation of quantum mechanics consistent with the above Einsteinian realism, such as the version of QBism by Fuchs.

Bohr's quote that there is no quantum world means that there are no Einsteinian hidden ontic states. It is a firmly positivist view. The XX century has proved the Bohr view to be correct (whether he said it exactly that way or not).

Update: A comment says of Bohr:

He invariably made ontologically neutral statements, such as "The formalism is to be regarded as a tool for deriving predictions, of definite or statistical character...".

That is how I interpreted "there is no quantum world", but I guess two views are possible: (1) there is no underlying ontology; or (2) quantum mechanics does not rely on an underlying ontology. The latter is the more positivist view, and presumably Bohr's view as well.

The possibility of these two interpretations may explain why Mermin had trouble confirming the quote.

Positivism means talking about what the theory can do for you. Positivists avoid metaphysical speculations. So a positivist would not say that there can be no other description of the world. I take Bohr's statement as a statement about quantum theory, and not a denial that other theories are possible. Quantum mechanics does not have a world of hidden variables with values for unobserved physical quantities.

Friday, April 14, 2017

Looking back at the origins of the relativity revolution, it is interesting to note that the main reason given at the Saint-Louis conference of 24 September 1904 by Poincare for hesitating at a full endorsement of the principle of relativity was that celestial mechanics had suggested that the speed of the gravitational interaction exceeded that of light by at least six orders of magnitude ([45], p. 312, [46], p. 134; cit. in [37], pp.779-80).

A few months later Poincare changed his mind, if tentatively, when he discovered what, in our terms, are the first Poincare-invariant formulations of gravitation. He announced and, respectively, described in detail these findings (among many others) in his two famous articles of 1905 and 1906 ([47], [48]). Historians of physics have often taxed Poincare with not being bold enough to espouse the new theory of relativity in the trenchant way adopted a few weeks later by a young patent office clerk, who nonchalantly disposed of the aether as “superfluous”.27

At an historical distance of more than a century Poincare’s hesitancy is worth our admiration for its methodological wisdom.

This is correct. Poincare was many years ahead of Einstein in relativistic analysis of gravitation and causality.

Yes, some authors are impressed by Einstein calling the aether superfluous, but he was just echoing what Poincare had been saying for many years. As early as 1889, Poincare predicted that “the day will doubtless come when the ether will be rejected as useless”. He repeated this in his widely-read 1902 book.

Capria has a lot of excellent detail on the history of special relativity in his 2011 paper. I had not seen this early, and it partially explains the bias against Poincare.

Wednesday, April 12, 2017

Why do physicists worry so much about the black hole information paradox, since it looks like there are several, more mundane processes that are also not reversible? One obvious example is the increase of the entropy in an isolated system and another one is performing a measurement according to quantum mechanics. ...

B: ... This problem has attracted so much attention because the mathematics is so clear-cut and the implications are so deep. ...

Excuse the cynicism, but that’s my take on the situation. I’ll even admit having contributed to the paper pile because that’s how academia works. I too have to make a living somehow.

So that’s the other reason why physicists worry so much about the black hole information loss problem: Because it’s speculation unconstrained by data, it’s easy to write papers about it, and there are so many people working on it that citations aren’t hard to come by either.

She gives more of an explanation, but as you can see, there is no good answer.

Burning a book destroys information. It is an irreversible process. Some theoretical physicists have a quasi-religious belief in reversibility, so they do not accept the information loss. But instead of arguing about what happens to a burning book, they argue about what happens when you toss a book into a black hole. That way they can say whatever they want, and no one can prove them wrong.

Monday, April 10, 2017

The term “quantum supremacy” is the fashionable name for the quantum experiments attempting to beat classical computers at some given task, not necessarily a useful one. According to current usage, the term (strangely) only applies to computational problems. The theoretical and experimental work towards demonstrating this is wonderful. But the term itself, as any native English speaker can tell you, has the unfortunate feature that it immediately calls to mind “white supremacy”. ...

The humor surrounding this term has always been in bad taste — talking about “quantum supremacists” and jokes about disavowing their support — but it was perhaps tolerable before the US election in November. Given that there are several viable alternatives, for example “quantum advantage” or even “quantum superiority”, can we please agree as a community to abandon this awful term? ...

Update: Ashley Montanaro points out that “advantage” should potentially be reserved for a slight advantage. I maintain that “superiority” is still a good choice, and I also offer “dominance” as another alternative.

: a person who believes that the white race is inherently superior to other races and that white people should have control over people of other races

What does this have to do with the November election? Almost nothing, except that the NY Times and others have been trying to expand usage of the term, such as in this:

Let us pause. Not even two years ago, white supremacists like Mr. Schoep would rant from the fringe of the fringe, their attention-desperate events rarely worth mention. Today, though, the Schoeps of America are undergoing a rebranding, as part of the so-called alt-right: a grab bag of far-right groups generally united by the belief that white identity has become endangered in what they deride as this era of dangerous diversity and political correctness.

So if someone says that political correctness has become hostile to white identity, then he might be called a white supremacist.

The term "quantum supremacy" has become common, and the quantum computing advocates do appear to believe in the inherent superiority of such computers, and that such computers should computationally dominate others.

Before the term became popular, I used terms like "super-Turing". We need some such term, because the interesting thing about quantum computers is that they promise to outperform a Turing machine and expand computational possibilities.

Quantum information science explores the frontier of highly complex quantum states, the "entanglement frontier." This study is motivated by the observation (widely believed but unproven) that classical systems cannot simulate highly entangled quantum systems efficiently, and we hope to hasten the day when well controlled quantum systems can perform tasks surpassing what can be done in the classical world. One way to achieve such "quantum supremacy" would be to run an algorithm on a quantum computer which solves a problem with a super-polynomial speedup relative to classical computers,

The technology for controlling quantum systems is advancing rapidly, fuelling the hope that in a few decades human civilization will enter an age of quantum supremacy, in which quantum computers solve problems that are beyond the reach of classical digital computers, such as factoring large numbers and simulating the physics of complex molecules. But to realize that dream, we must overcome a formidable obstacle: that of “decoherence”, which ordinarily makes large quantum systems behave classically. Entanglement among the qubits in a quantum computer is the source of its power, but entanglement between the computer and its unobserved environment is our enemy, driving decoherence.

Does this sound like white supremacy to you? If I change a few words, I get:

The technology for controlling modern systems is advancing rapidly, fuelling the hope that in a few decades human civilization will enter an age of white supremacy, in which white men solve problems that are beyond the reach of non-whites and women, such as managing large nations and simulating the sex habits of Jewish perverts. But to realize that dream, we must overcome a formidable obstacle: that of “black lives matter”, which ordinarily makes large diverse systems behave like animals. The secret handshake among the elites in a white-dominated nation is the source of its power, but integration between the whites and its unobserved environment is our enemy, driving desegregation.

No, I pretty sure that Preskill is not a Nazi writing in code.

Google might be run by Nazis. It appears to be on a mission to destroy our privacy, and building a computer to factor large numbers would be a step towards that goal.

There is something creepy about quantum computing, like Nazi eugenics. It is very ambitious, technologically hopeless, and immediately harmful to most ppl. I do not think that we need to try to stop it because it will fail anyway.

Tuesday, April 4, 2017

Another factor that conjures in hiding the role of human judgment in science is the fiction that there is such thing as a quasi algorithm-like thing called “the scientific method.” While philosophers of the early part of the 20th century kept searching for it, the consensus nowadays is that it doesn’t exist. Yet scientists themselves help perpetuate the myth, both in references to the phantomatic method in introductory textbooks, and also by creating “the false impression of a regular, orderly method by writing up their findings in ways which gloss over the real messiness of discovery.” ...

Here is one gem from the chapter: “Another of Einstein’s remarks is extremely revealing. He once said, ‘I find the idea quite intolerable that an electron exposed to radiation should choose of its own free will, not only its moment to jump off, but also its direction. In that case, I would rather be a cobbler, or even an employee in a gaming-house, than a physicist.'” This is an expression of a strongly emotionally held aesthetic judgment. Nothing to do with physics or mathematics as ordinarily understood, or the quest for truth, for that matter.

I post this to show how anti-science modern philosophers are. They have a consensus that there is no scientific method!

The Einstein example is particularly revealing. Einstein is famous for allowing his quasi-religious prejudices to reject quantum mechanics. Mainstream physicists all accepted quantum mechanics, and considered Einstein to be intellectually senile.

Yes, Einstein used emotional and aesthetic opinions to reject a perfectly good. How does this disprove the scientific method? The quantum theory was accepted on the merits, and Einstein's unscientific objections were not.

Here is another silly argument:

My favorite example among those cited by Julian is Boyle, who was “persistent in holding to his theory when observation refused to confirm it. On 49 occasions he tested his hypothesis that smooth bodies that stuck together in air would come apart in a vacuum, without success, yet succeeded on the 50th attempt.”

I would assume that he had some good reasons for his persistance. Pigliucci assumes that he was unscientific, or not following a scientific method.

I might attempt to run a marathon 49 times, and finally succeed on my 50th attempt. Does that mean that I am stupid, or unscientific, or failing to learn from my experience? Of course not.

If there is a common thread in philosophy today, it is that they do everything they can to deny truth, to deny knowledge, and to deny science.

As in the case of a poll Baggini cites from 1999: when 90 leading physicists were asked which interpretation of quantum mechanics they thought was best, 4 voted for Copenhagen, 30 for Many Worlds, and 50 said either none of the above or undecided. ...

Scientists — below the surface, mostly in private or informal exchanges — even disagree on major issues of epistemology and metaphysics. For instance, “Bohr … completely rejected scientific realism. ‘There is no quantum world. There is only an abstract quantum mechanical description,’ he said. ‘It is wrong to think that the task of physics is to find out how nature is. Physics concerns what we can say about nature.'” Needless to say, a number of his colleagues disagreed vehemently, thus unwittingly engaging in philosophical debates about the nature and scope of their discipline.

It is embarrassing that so many physicists subscribe to Many Worlds, as that is an unscientific idea. But Bohr was simply being a logical positivist, and his view is what was adopted by the textbooks. It was only rejected by a few cranks like Einstein, Bohm, Bell, and a bunch of modern philosophers.

Modern philosophers hate positivism because they hate the idea of scientific truth.

And of course beauty and aesthetics are not, in fact, guarantors of truth: “As George Ellis and Joe Silk point out, ‘Experiments have proved many beautiful and simple theories wrong, from the steady-state theory of cosmology to the SU(5) Grand Unified Theory of particle physics, which aimed to unify the electroweak force and the strong force.'”

No, those theories are not beautiful or simple. A steady-state cosmology requires strange forces for counteracting gravity, something for making an equilibrium, some way of creating stars, etc. It is a mess. The SU(5) theory is much more complicated than the Standard Model, as it requires about twice as many bosons, and many more free parameters that would have to be determined by experiment.